Studies on the Trigeminal Pupilloconstricting Nerve

I. Neurohumoral Transmission (A)- Pupillary Reactions and Reactions of Leech Dorsal Muscles

Abstract

1) It is demonstrated that the aqueous humor of a bull-frog which has developed a pupillary constriction due to stimuli on the trigeminal pupilloconstricting nerve (“trigeminus aqueous humor”) possesses a pupilloconstricting action on another medullary frog.
2) A pupilloconstricting action of “trigeminus aqueous humor” is increased by eserine and abolished by atropine. It is demonstrated that the aqueous humor subject to stimulation of efferent trigeminal pupilloconstricting nerve contains an Ach-like substance.
3) The pupilloconstricting effect of “trigeminus aqueous humor” is similar to the effect of “oculomotorius aqueous humor”.
4) The eserinized “trigeminus aqueous humor” has a contracting action on eserinized leech dorsal muscles.
5) The contracting effect of “trigeminus aqueous humor” corresponds with the contracting effect of a 10-6 to 10-8 Ach-Ringer's solution on leech dorsal muscles.
6) A neuro-effector transmission of the trigeminal pupilloconstricting nerve seems to have been ascertained by Ach-mechanism.